This is a special group. The dance company or -- -- ABC news digital special report fired up. And ready to go border council on the Korean Peninsula evacuated today after a wild volley of artillery shells between the north and south. 500. Were fired into South Korean waters today. So in retaliation. Soul shot 300 -- of its own in -- North Korean waters all of this. As a north Koreans threatened more nuclear tests. He's not exactly a sport now from New York -- Hi again as you know. Military provocations and the occasional military of fire between these two countries is nothing -- what isn't concerned however is this looming nuclear threat. Along with the promises -- there North Korean leader Kim Jung -- That they were going to continue some new nuclear testing. The US and South Korean military continued to perform two point exercises -- -- Hong. On the southeastern part of the peninsula on Monday. While closer to the northern border real military engagement forced the evacuation of South Korean residents. For three hours north and South Korea exchanged artillery fire. While the rhetorical fire continues. Yeah. It would that is North Korean media reported that those US south Korean War exercises were an attempt to occupy Pyongyang. And that the north would be taking steps which the west could quote hardly a mention recent tensions on the peninsula have spiked. With North Korea testing in -- -- And a threat that Pyongyang will be carrying out a new form of nuclear test meanwhile North Korean media stoke the flames and their public. I'll put -- on wall. The south creams are carrying out vicious activities this North Korean worker says -- cannot forgive that while general -- Kennedy disputed. That these exercises -- a form of aggression. This exercise is not designed to do to react to any political situation it's not. Designed sent a message this is something else that we have to do you feel that in -- -- with our allies. And it is exactly a year ago that these escalating tensions in the Korean Peninsula threatened to erupt into all out war. The hope this time Dan is that of course that situation can be calmed before we get to that point Lana -- ABC news New York. -- want to thank you for that on the back and forth now between the Koreas are so for more on the content to wanna bring it ABC's -- Martinez. Who -- about the Pentagon -- if North Korea says it feels threatened by the US military exercises that it conducts jointly with the south there. The fact that in. The country and in fact did so today is it a wise move as they're rethinking going on right now. I'm not really again what to -- these exercises are an annual event and it's also become an annual event that the north Koreans are going to respond to them with provocative action. It's actually known here at the Pentagon as the cycle of provocation. That was one of the questions that was asked the secretary -- today it is just concluded a news conference. And one of the questions that we all -- was you what you do what you're saying actually is it's a -- it's unfair question. Are these. Exercises provoking the north Koreans and should continue if that's going to be the case when we talk to military officials what they told us says that. These exercises need to take place to reaffirm America's commitment to South Korea and -- -- stability of the region. -- and that it doesn't matter that the north Koreans reactive in negative ways. Because they are there to respond as well if needed and as we've known over the last couple years South Korea has said that they will respond. Which is one of the reasons why we sobbed. For the retaliatory artillery rounds headed back North Korean waters last night in fact I do want to play with the secretary of has just had to say just a short time ago. Who have provocation that the north. Koreans -- Once again engaged in is dangerous. And it it needs to stop. So no threat of a response from the US who wise. Well if anything I think American officials want to downplay the incident because. They don't want to North Korea to continue to ratchet up this kind of -- reaction you're getting a very direct confidence -- secretary defense saying you know. You're engaging this proud and these kinds of provocations. Stop it BK is that they're not conducive. Two stability on the Korean Peninsula last week we know that. North Korea launch these two medium range missiles -- from their West Coast. Across the Korean Peninsula landed in the waters there -- -- Japan. A major provocation because -- country is not allowed to fire ballistic -- by. A UN security resolutions of the United States said. We're -- consult with our allies and -- -- -- come up with additional measures. To -- maybe a punitive measures against North Korea and that's exactly what happened they went to the new UN Security Council. And discussed it it's still unclear whether there -- new expansions are -- emerge from that. But the message is clear to North Korea that for the international community does not support -- -- in these kinds of provocations. Now -- an example you know the these rocket -- of these rocket firings habitat for the last couple weeks yourself. They -- these. These are pretty much not to strategic missiles so there. They're not -- they don't really -- US or South Korean officials. But it is indeed -- them without any warning and so therefore these -- missiles could be fired into let's say. Incoming air traffic or if there -- ships that in an area where these missiles could land. And that's one of the things that really concerns. Officials on the South Korean side. In the fact that these events take place with little warning. And it's not so much the strategic effect as what kind of -- and have a civilian craft and a strong response from both sides there 800 shells in total. A bit of an excessive response that because of these exercises. Actually -- and -- last year in the -- South Korea. Weighs on the verge of military action against North Korea because of their provocative behavior. If anything in the United States had to -- -- in the South Korean leadership because they were ready to respond any significant way. It was part of the what do you heard that piece there about the ratcheting up of -- last year that was really the most severe in years. So what we see now with this retaliatory. Rounds being fired. And to North Korean waters is pretty much we are not gonna sit back on the part of -- -- South Koreans are saying we're not sit back. We are going to if you were going to do something along these lines -- gonna match you. Q I'll let you know that we are on alert as well now the North Korea is saying that it wants to conduct a fourth nuclear test. Cause for alarm what's from the US response to that. Well one it's -- -- -- it because it's unclear exactly what is -- mean we've known that they've had these tests before these underground -- at the same facility. We've got there in north -- North Korea. -- -- what we think is happening is that they have in the past triggered these small. Explosive type. Uranium based explosions so maybe what they're talking about here is -- stepping up to the next level which would be -- plutonium based. -- Which I think they try to -- -- in the third time but it's really unclear what they mean by this new type of test. If anything either way it's going to be regarded as a provocation on the peninsula because again there's so many UN Security Council. Un resolutions barring any kind. Of activity like this on the part of North Korea either of ballistic missiles and missile testing and nuclear test in what has been the response of nearby Japan. China where -- -- and their reaction to this. Well so far it's been kind of needed and in terms of what we -- -- was a lot of concern during a ballistic missile launches last week. Which of course resulted in action at European Security Council but in -- part of south out of China it's always a little bit more muted because they do support. The -- north -- leadership. The question is why do they do that the answer weekend is that they want stability on the north Korean Peninsula regardless of how it happens they don't want to see. Crisis emerge on their eastern borders where there is instability leads to a power struggle. In North Korea that could be -- -- flow of refugees they want to avoid that at all costs. So they each basically provide needed support to the North Korean leadership that's -- -- is -- he said we heard secretary England this news conference just now say that. When I go to China this week and I'm certain that this is going to be one of the topics that I talk about with the Chinese leadership. Was speaking on the North Korean leadership Kim Jong has been in power -- for three years he was just. Reelected. It for lack of a better term a process that occurs in that country there is unanimously earlier this month. Do American intelligence officials they have a better read on him since that first power began three years ago. They have been that is a better read on the in terms of intelligence part what. He's -- pattern of behavior is. But but one thing that is consistent. And that we keep hearing from official is that he is uncertain and if there's a lot of uncertainty. About what he really wants to do so we have these three years now you'd expect some kind of predictable behavior were not at that point. But what we do know. Is that there remains the concern that he is an uncertain cannons and unstable character. Who can that lead to -- certain decisions. And that's something that of course is of concern when we had that incident where his uncle was taken out and executed them for whatever reason just a couple of months ago. That was of concern to. Officials across the intelligence community and again reflected the nature that. We know very little about this leader who has. Control of a massive army. And as sort of small nuclear -- so of course he is of concern but it's still unclear how if where they can predict anything in his behavior. If anything the only thing we can't predict is that he is unpredictable there. Is an American being held in North Korea can't pay -- you've been there for about a year now what is the latest update on his condition. -- look he has been put into. Hard labor camps. I he had an episode a couple of months ago where he had he was doing so -- health wise that he had to be taken. -- to a hospital the United States doesn't have diplomatic relations with North Korea so we ask an intermediary nation in this part Sweden. Go in and check on his on our behalf to see how he's doing. We got very basic information about how he's doing and the next thing we heard was that he had been sent back for the labor camp. -- North Korea just -- very intent on not letting go of this individual the United States just as determined. To seek for his release whenever the top US officials head over to the region. -- -- raise it with regional partners. And they always -- in a public form that. Kenneth they should be released because if you he's done nothing wrong the latest back and forth going on the Korean Peninsula eighties his liberty has the pan am really thank you for that appreciate it. At a -- -- -- over the -- real time by downloading the ABC news app. And starring the story for exclusive updates on the go.

This transcript has been automatically generated and may not be 100% accurate.

North and South Korea Trade Fire Amid Evacuations

South Korea officials say that hundreds of artillery shells were fired into the Yellow Sea.